Apparatus for mixing and purifying fluid mediums



May 11, 1965 E. ERNI 3,182,977

APPARATUS FOR MIXING AND PURIFYING FLUID MEDIUMS Filed Sept. 26, 1960 6 Sheets-Sheet 1 INVENTOR. E/vm'co ER/w' A TTORNEY E. ERNI 3,182,977

G AND PURIFYING FLUID MEDIUMS May 11, 1965 6 Sheets-Sheet 3 Filed Sept. 26; 1960 INVENTOR. v Ewe/co Elam" ATTORNEY May 11, 1965 E. ERNI 3,182,977

APPARATUS FOR MIXING AND PURIFYING FLUID MEDIUMS Filed Sept. 26, 1960 6 Sheets-Sheet 4 INVENTOR. Emma 50 B zzw a M A TTOR NEY E. ERNI May 11, 1965 APPARATUS FOR MIXING AND PURIFYING FLUID MEDIUMS Filed Sept. 26, 1960 6 Sheets-Sheet 5 INVENTORM. 44m: 5PM m Imam A TT ORNE Y May 11, 1965 E. ERNI 3,182,977

APPARATUS FOR MIXING AND PURIFYING FLUID "EDIUIS Filed Sept. 26, 1960 6 Sheets-Shack 6 IN VEN TOR.

5WD 5244 arm 0- mm;

- A TTORNE Y V spraying disks.

3,182,977 APPARATUS FOR MKXING AND PURIFYING FLUID MEDIUMS Enrico Erni, Muhlacker, Gerlafingen, Switzerland, assignor to Gesellschaft der Ludw. von Rollschen Eisenwerke AG, Gerlafingen, Switzerland, a corporation of Switzerland Filed Sept. 26, 1960, Ser. No. 58,277 Claims priority, application Switzerland, Sept. 29, 1959, 78,815; Nov. 13, 1959, 80,581; May 18, 1960, 5,695/60 5 Claims. (Cl. 261-112) The present invention relates to an improved apparatus for mixing together fluid mediums, as for example, the

physical procedures: Wetting, evaporation, absorption,

concentration of solid particles in liquids, and elimination of solid particles from a gas stream. The size of the solid particles preferably varies between a few Angstro-rns and the millimeter limit.

Methods of mixing liquids in gas streams by means of atomization processes are known wherein the liquid is sprayed in dispersed condition into the gas stream by means of auxiliary equipment. Such auxiliary equipment is used in order to provide the additional energy necessary to supply theliquid in a sprayed condition, and may preferably be in the form of pressure pumps United States Patent 0 operating in conjunction with suitable nozzles of any known construction, balfle plates, and centrifuging or However, the use of such auxiliary equipment for carrying out this method of mixing fluid mediums has certain marked '{disadvantages For example, if the liquids to be introduced into the gas stream are charged with solid particles, which is often the case in a wide variety of applications, this auxiliary equipment requires that it be continually serviced. Furthermore, the mere use of such auxiliary equipment necessitates that a certain power requirement be met andalso causes increased costs of the installation of said equipment. 1

v The present invention relies upon the principle of the physical behavior of gases moving in a stateof unsteady flow and building up a turbulent zone in a pronounced extension of the cross-section of a flow passageway. If another gas or liquid is introduced into this turbulent zone, a homogen-ous mixture of these separate mediums results without requiring the use of any special auxiliary equipment. If the velocity of the gas stream in the small- :est cross-section of the flow passageway does not fall below a certain value the liquids may be very finely sprayed, According to a preferred embodiment of mixing gases with liquids, the gas stream is passed over a fluid film undergoing a cascading effect, said fluidfilin being atomized or (finely dispersed upon entering a pronounced narrowing of the cross-section of the flow passageway. The liquid is then able to almost completely absorb and remove any solid particles contained in the gas.

The basic features of the device for carrying out the teachings of the present invention is characterized by two plane, substantially flat and preferably relatively movable surfaces which are directed toward one another Patented May 11, 1965 spray like or finely dispersed liquid is formed which is able to easily mix with the gas stream and remove lmpuri-ties there-from in .a reliable and efficient manner.

' The device according to the present invention possesses at least three primary advantages over these heretofore known in the art, namely: (1) there is no necessity for providing auxiliary equipment to supply the liquidrmedium in finely dispersed condition into the gas stream; (2) there is ensured an accurate and reliable adjustability of the supply of gaseous medium; and (3) the device is capable of functioning and handlingliquid mediums containing solid particleswithout any difliculty.

Accordingly, it is an important object of the present invention to provide improved means for efiiciently and reliably mixing together fluid mediums, one of said fluid mediums undergoing an atomization process so as to be in :finely dispersed condition without the necessity of em ploying auxiliary equipment. a

It is a further object of the instant invention to provide means for efficiently andcheaply mixing together liquids and gases; and further, removing undesirable particles from said gases if desired.

Yet another object-of the present invention is to provide means for effectively dispersing a liquid medium in a fine, spray-like condition without requiring the usage of spraying or other auxiliary equipment.

Another object of the present invention i to provide a novelly constructed mixing chamber wherein spray-like- A further important object of the present invention is i to provide means for feeding a liquid medium into a gasstream to effectively and economically eifectuate mixing thereof in a safe and reliable manner.

These and still further objects of the present invention and the entire scope of applicabilit thereof will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

In the drawings:

FIGURE 1 is a perspective view diagrammatically illustrating theconstruction of a flow passageway and mixing chamber designed pursuant to the present invention;

FIGURE 2' is a diagrammatic View of a preferred embodiment of a mixing apparatus pursuantto the present 7 invention and provided with a pair of nozzle bodies and separate supply chambers for the liquid medium; FIGURE 3 is a diagrammatic sectional view of an axially symmetrical mixing apparatus designed according V FIGURE illustrates a fragmentary cross-sectional view of dust-collecting plant employing an axially symmetrical installation pursuant to the instant invention;

FIGURE 5a schematically illustrates a possible recycling arrangement for the waste liquid removed from the system; and

FIGURE 6 is a diagrammatic and fragmentary view of an axially symmetrical embodiment of a device designed pursuant to the teachings of the present invention provided with two supply chambers for the liquid medi- Referring now in greater detail to the drawings and, more specifically to FIGURE 1 thereof, there is diagrammatically set forth the basic concept of the present invention, comprising a hollow housing or body member A of rectangular cross-section defining a flow channel or passageway 3 through which a fluid medium, as for example a gas, travels in the direction of the arrow B. For clarity of illustration the front wall of the housing member A has been removed to thereby expose the interior of the flow passageway 3. The housing member A supports on its inner walls a pair of inclined, substantially flat or plane surfaces 1 and 2 which are situated in respective planes converging toward one another. In the illustrated embodiment of FIGURE 1, the flat surface 2 is adapted to be displaced in the direction of the double-headed arrow CC to provide together with the fiat surface 1 an adjustable cross-sectional constriction or nozzle opening in the flow passageway 3. A suitable supply chamber 5 communicating with the flat surface 1 via the opening 7 is supplied with a liquid medium, such as water, by means of a supply line 6. A screening bafile or shield 8 disposed above the opening 7 extends substantially parallel to the flat surface 1 to define therewith a channel or slotted opening 7a. The liquid medium flows through the slotted orifice 7a and onto the fiat surface 1 to form a liquid film thereon. The liquid film upon reaching the edge 1a of the fiat surface 1 cascades therefrom into the constricted region 4 between the respective edges 1a of the flat surfaces 1 and 2, the cross-sectional area of which may be variably adjusted due to displacement of the flat surface 2 in the direction of the double headed arrow CC.

The battle or screening member 8 protects the supply chamber 5 from the effects of the gas stream moving in the direction of the arrow B down the length of the flow passageway 3, and also, maintains and provides uniformity of the liquid film as the liquid medium emerges through the opening 7. The liquid film flowing downwards on the fiat surface 1 is finely dispersed or atomized under the effects of the gas stream moving in a state of unsteady flow and in its most turbulent condition primarily in the constrictive region 4 where the cross-section of the flow passageway 3 is most restricted. The degree of atomization or dispersion of the liquid, that is to say, the size and size distribution of the atomized liquid medium is substantially determined by the dimension of the fiow passageway and the turbulence present in the region around and downstream of the constricted region 4. The gas or gas mixture is mixed in the space 9 with the atomized liquid medium. It should be pointed out that the use of plate-like flat surfaces 1 and, 2 is generally not favoured due to the formation of eddy currents on the underside of said plate-like fiat surfaces, and accordingly, it has been found desirable to make the flat surfaces 1 and 2 portions of suitable contoured flow profiled nozzle a receiver for the liquid-gas mixture may be arranged in the direction of the outflowing mixture, or there may be provided a separating zone wherein the liquid may be separated from the gas under the action of a gravitational field in a steadying chamber or by means of a cyclone. The liquid prior to separation having effectivel removed undesired impurities from the gas stream should it be so desired.

In FIGURE 2 there is shown a mixing apparatus wherein the two fiat surfaces 11 and 12 lying in converging planes form part of the relatively movable and adjustable nozzle members 13 and 14 which are, in the form of triangular blocks, disposed internally of the housing or body member A defining the flow passageway 3. The nozzle member 14 is adapted to be displaced within suitable guide rails 14b shown in dotted lines in the direction of the double-headed arrow C-C to vary the spacing between respective nozzle members 13 and 14. Suitable sealing members 15 and 16 are interposed between the back face 14a of nozzle member 14 and the inner wall 17 of the housing or body member A. The nozzle members 13 and 14 cooperate with one another in spaced relation to form the constricted nozzle region or opening 18 of varying cross-sectional area due to displacement of the nozzle member in the direction of said arrow CC. The flat surfaces, portions 11 and 12 of nozzle members 13 and 14, respectively, receive a supply of a liquid medium from the channel-shaped supply chambers 19 and 20 via the delivery openings 23 and in registry with said respective flat surfaces 11 and 12. A separate bafiie member 21 and 22 is disposed above and adjacent to the flat surfaces 11 and 12 to define a channel-shaped or slotted opening 21a through which the liquid emerges. These baflie members also serve to protect the supply chambers 19 and 2%) from the gaseous medium flowing down the inside of the body member A toward the triangular shaped nozzle members 13 and 14. The liquid medium is deposited onto the flat surfaces 11 and 12 as a liquid film and cascades over the respective edges 25 of said nozzle members into the restricted flow region 18. For the sake of clarity, the supply lines for the supply chambers 19 and 20 have not been ilustrated but may be similar to those shown in FIGURE 1. It is to be appreciatcd that the supply line for the supply chamber 20 of bodies. Depending upon the particular use of the device, I

the movable nozzle member 14 must be designed so as to be correspondingly flexible and adjustable in its posiion.

The gas stream flowing through the flow passageway 3 of the housing or body member A at a relatively high rate of speed atomizes or finely disperses at least a portion of the liquid film cascading over the edges 25 of the nozzle members 13 and 14. The region of turbulent gas flow approximately begins at the edges 25 of said nozzle members and extends downwardly into the space 27 downstream of said nozzle members 13 and 14. It is to be appreciated that a certain degree of unsteady flow of the gas stream starts in the region where the flat surfaces 11 and 12 begin to converge toward one another. However, the most effective region of liquid dispersion is at the point where the liquid film cascades from said flat surfaces and downstream therefrom. By suitably adjusting the supply of the liquid medium to the flat surfaces 11 and 12 it is possible to have an excess of liquid, beyond what may be effectively atomized by the gas stream, fiow down the inner wall portions 28 and 29 of the body member A to exert a cleaning action on said wall portrons. This has proven to. be especially advantageous if the device is employed in the removal of dust or other undesirable particles from the gaseous medium in order to prevent the accumulation and depositing of solid particles on the walls of said housing member A.

It is to be understood and appreciated that the device of the present invention is not limited to flow channels having arectangular or right-angled cross-section. Moreover, the nozzle bodies may be designed annular and coaxially arranged so that the nozzle opening or restriction through which the cascading liquid film and the gaseous medium pass are also of annular cross-section. Such a design of a mixing chamber which has proven to be extremely advantageous in many applications is clearly shown in FIGURE 3.

Furthermore, it is possible in all embodiments of the invention to design either one or both of the nozzle members so as to be movable. Particularly when employing an axially symmetrical design-0f the mixing chamber it is desirable to make the inner or outer or both nozzle members movable to permit adjustment of the restrictive nozzle opening through which the fiuid mediums pass.

In FIGURE 3 there is illustrated a mixing chamber wherein one nozzle member 30 is rigidly supported by the Wall 32 of a housing or body member A having a circular or annular cross-section. Of course, the nozzle member 30 may be formed integral with the wall 32 or else be separately connected thereto. The other nozzle member 31 may then preferably be arranged so as to be axially symmetrical, and for example, in the shape of a double cone having abutting base members which is movably supported on a hollow tubular shaft member 38. The nozzle member 31 is displaceable in the direction of the double-headed arrow C-C and coaxially arranged in the fiow channel 3 with respect to the outer stationary nozzle body 30. Supply lines 33a supply a liquid medium to the supply chambers 33 designed in the form of an annular channel. The liquid medium passes into the fiow channel via the slotted opening 34, the upper extremity of which is defined by the baifie portion 32a of wall portion 32. The emerging liquid passes over the fiat surfaces 35 of the nozzle bodies in the form of a liquid film and then cascades oil the edge 35a thereof into the restricted nozzle opening 36. At this point the cascading liquid film is mixed with the downwardly flowing gas stream resulting in atomization or fine dispersion of at least a portion of said liquid film. Should the device be employed for the purification of gases, it is preferable to spirally feed the gas stream in its downward direction about'the axis AA', the chamber 37 leading into a suitably provided cyclone. In the cyclone the rotating gas is caused to separate from the liquid and passes upwards through the tubular shaft member 38 in the direction of the arrows D. The liquid medium WlllCh has been atomized by the dust-carrying gas stream absorbs a large portion of the solid particles contained in the gas,

such as dust in the region of turbulent gas flow created by the restricted nozzle opening 36. These particles are then able to be removed from the gas together with the liquid upon leaving the chamber 37. A certain amount of separation of the gas already taking place in chamber 37 due to the elfects of gravity.

The-liquid medium which is to be finely dispersed can be tangentially supplied to the annular supply chamber 33 or in any other known manner such that it is caused to rotate about the longitudinal axis AA. Such rotational movement of the liquid has been represented by the concave surface of said liquid as depicted in FIGURE 3. The advantage of introducing the liquid in this manner resides in the fact that, for example, water containing solid particles may be employed for the purification of gases. Thus, it is possible to reliably prevent the deposit ing and sedimentation of solid particles-in the supply chamber 33 by imparting such rotational movement to the liquid medium. The rotational speedof the liquid medium in the supply chamber 33 must be greater than the velocity at which the solid particles contained therein are carried along. The arrangement shown in FIGURE 2 may also be employed for thecleaning or purification of gases. However, in order to provide trouble-free operation of the device, relatively purewater should be employed unless special means are provided which positively prevents the depositing of solid particles in the supply chambers as already detailed hereinabove.

In FIGURE 4 there is shown a further arrangement of a device designed according to the teachings of the present invention and adapted to be employed in a purification plant for industrial gases. The gas which is to undergo purification is supplied to the inlet chamber 39 and flows downward through the restricted and adjustable nozzle opening 452 defined by the relatively movable nozzle members 40 and 41. The nozzle member 40 is designed to be movable in suitable guideways in the direction of the double-headed arrow C--C to permit adjustment of the restrictive nozzle opening 42. The two fiat, converging surfaces 43 and 44 of the nozzle members 40 and 41, re spectively, are supplied with water from the supply chambers 45 and 46. The water flows in a downward direction along these surfaces in the form of a film and is at least partially atomized by the on-coming gas stream, An intensive mixing of the gas to be purified and the previously finely dispersed water takes place in the downstream located ditfuser or mixing chamber 47, the water absorbing a major portion of the solid particles contained in the gas in the process. A steadying and separating chamber 48 disposed downstream of the intensive mixing chamber 47 enables the Water together with the absorbed solid particles to be deposited and removed by the drain 49 provided for the waste water. The purified gas flows through the gas outlet 50. In order to make certain that the entire volume of the gas to be purified is retained internally of the system andis' exposed to treatment, the displaceable nozzle member 40 is provided with sealing members 51 contacting the inner wall 51a of the housing member A.

In FIGURE 5 thereis shown, a vertical sectional view of a dust removal plant for industrial waste gases incorporating the preferred axially symmetrical design of the mixing and purification apparatus accordingv to the present invention. The liquid medium herein employed, by way of example, may be Water. The gas to be purified, such as a waste stack gas containing ferric oxide produced as an after product in metallurgical plants flows downward from the gas intake or inlet chamber 60 in the direction of the upper arrow B and towards the nozzle restrictive opening 65. The device is constituted by the housing or body member A, adjacent the upper end of which is provided an annular inclined flat surface 61 which forms together with the wall 63a thereof a stationary nozzle member generally designated by reference nuare covered by a liquid film' formed by a supply of water received from the outer and inner supply chambers 66 and 67 arranged alongside of, and in registry with, said flat surfaces 61 and 62. Both the inner supply chamber 67 and the outer supply chamber 66 are provided at their upper end with the balfie or screening members 68 and 69. For the sake of clarity, the supply lines delivering the Water to the supply chambers 66 and 67 have not been shown. It is readily to be appreciated that the supply line feeding the supply chamber 67 must be made flexible since this inner supply chamber 67 and its bafiie member 68 is movable together with then'ozzle portion 64.

A'displacement of the nozzle member 64 in the direction of the double-headed arrow C-G etfectuates an adjustment and variance of the nozzle restrictive opening 65. This enables the dust removal and purification apparatus to be adjusted in accordance with the operatingconditions of the gas generator associated therewith. As the volume of gas produced varies, an automatic control device of conventionaldesign, as for example any suitable, electric, pneumatic or hydraulic control, can be employed to carry out the adjustment of the nozzle opening by causing produced is, of course, dependent upon the velocity of flow of the gas stream. It has been found advantageous if the water employed for the removal of dust or other undesirable particles from the gas stream, itself contain solid particles, since it has been found that liquids containing solid particles will generally better absorb the solid particles, such as dust carried by the gas stream, than liquids in a pure state. By designing the annular supply chambers 66 and 67 so as to be axially symmetrical it is possible to impart to the incoming water a rotational direction of flow in the annular chambers, thereby preventing a depositing of solid particles on the walls thereof in a manner already described in detail hereinabove. The rotational movement given to the incoming water can be produced by any suitable means, as for example guideways or nozzles for dirccting the passage of the water into the annular chambers, by means of pumps or any other known conveying means.

In order to effectively prevent a depositing of solid particles removed from the dust or impurity laden gas on the inner walls of the tubular housing A of the dust removal device, it is only necessary to supply a greater quantity of Water to the device than the gas stream is capable of atomizing. The excess water scavenges and wipes the walls of the nozzle members 63 and 64, particularly in those areas wherein the dust can most easily contact said walls. Such a cleaning action is particularly significant for the outer wall 63a should the dust laden gas be rotatably guided in a spiral path about the longitudinal axis of the dust removal device, since the centrifugal forces will cause the heavy particles to be deposited on this outer wall 63a.

After the dust laden gas has been thoroughly mixed with the finely dispersed or atomized water in the region of turbulence of the diffuser portion 74 of the mixing chamber, the solid and water particles will be deposited therebelow under the action of centrifugal forces or of gravity, depending of course upon the prevailing flow conditions. Disposed below the diffuser portion 74 there is provided a steadying or separating chamber 75 for effectuating a practically complete separation of the gaseous medium from the liquid medium and the solid particles removed from said gaseous medium. The purified gas thereafter fiows upwards in the direction of the arrows D through the interior funnel portion 64a of the movable nozzle 64 and thence through the outlet stack 76 arranged at the upper end 64b of said funnel portion 64a. Additionally, the water containing the solid particles is removed by gravity feed via the waste water drain 77. Since it has been found desirable to recirculate the water containing said solid particles, it is necessary to only replace that volume of water which has been removed by vaporization in the gas stream. A make-up supply of fresh water and/or addition of further solid particles to suitably adjust the content of solids in the water to any desired value can easily be provided for the supply chambers 66 and 67 in any known manner. The provisions of suitable sealing rings 79 for the stationary and movable nozzle portions 63 and 64 and for the actuating control rod 78 displacing the nozzle 64, which rod is displaceable in the direction of the double-headed arrow EE, prevents the escape of gas or entry of air into the apparatus. As a result of the recycling step, it is possible to obviate the use of costly precipitating devices for the complete purification of the Waste water while also permitting a reduction in the consumption of fresh water. A suitable arrangement for recirculating the waste water as schematically shown in FIGURE a consists of a mixing vessel M provided with respective supply lines 100 and 101 for the removed waste water and the make-up fresh water received from the source S, said supply lines communicating with and feeding the annular supply chambers 66 and 67. It is to be noted that it will thus be possible to limit the consumption of the fresh make-up water used by the apparatus to the volume of the water removed from the system due to evaporation and vaporization in the gas stream. Moreover, the entire design and arrangement of the dust-removal and purification system is relatively simple and extremely economical in comparison to the heretofore known prior art systems.

A dust removal device built in accordance with the teachings of FIGURE 5 had the following dimensions and the following conditions of flow were observed:

The overall diameter D of the device was 1750 mm.; the diameter D of the outer extremity of the movable nozzle 64 was 1450 mm.; the height H of the device was 3100 mm; the volume of gas Q, passed through the device was 3600 Nm. /h. (normal cubic meters per hour); the temperature t of the gas supplied was between 600 C. to 1000 C.; the temperature t of the gas removed was about 50 C. With a solids content of an industrial waste gas containing ferric oxide in the amount of 20-50 gms./Nm. (grams per normal cubic meter), the mean amount of solids separated was in the order of 94%. The circulating volume of Water Q amounted to about 120 m?/ h. (cubic meters per hour) and the effective consumption of make-up water when the waste water is recirculated under these conditions amounted to about 5 m. h. (cubic meters per hour). The velocity of the gas stream in the narrowest cross-section of the adjustable nozzle opening and which should not be reduced if the fluid mediums employed (such as industrial gases and water) are to be atomized to the optimum degree is 80 meters/sec. The mean dust concentration in the recycled waste water was found to be 8 gms./liter in the hereinabove disclosed example.

A further possible design of the device according to the present invention employing an axially symmetrical arrangement of the mixing and purification apparatus adapted to be employed as a dust removal installation for industrial gases is shown in FIGURE 6. In this embodiment there is provided in the housing A two stationary and concentrically arranged supply chambers 83 and 85 for the liquid medium. The housing A is provided adjacent its upper end with a gas inlet portion 80 through which the gaseous medium enters the apparatus. Mounted internally of the housing A is the displaceable nozzle portion 84 movable in the direction of the double-headed arrow C-C by means of the actuating rod 88. The movable nozzle portion 84 cooperates with the annular flat surface 89 provided on the housing A to thereby define an adjustable and restrictive nozzle opening 81. The gas inlet portion may be provided with a spiral guideway (not shown) of known design to impart a rotational and spiral movement to the gas which subsequently flows through the annular outlet 90 in the direction of the arrows F toward the restrictive nozzle opening 81. The gas inlet portion 80 is provided with a cooling jacket 91 to permit water cooling of the inlet portion 80. The gas upon leaving the restrictive nozzle opening 81 enters into the downstream mixing or diffuser portion 92 where it undergoes further mixing with the liquid medium now in dispersed condition. The stationary nozzle member 82 of the housing A may be formed in the manner as previously described with respect to FIGURE 3 and is associated with the supply chambers 83 and 85 carried by said housing A. Similarly, bafile or screening members 93 are arranged to cooperate with the annular flat surfaces 89 and the supply chambers 83 to protect the latter from the gas stream and to control depositing of the liquid medium in a film-like manner on said flat surfaces. The inner movable nozzle member 84 is formed as'a conical tube having a smaller degree of divergence below the nozzle opening 81 than the stationary nozzle member 82. The purified gas may flow through said conical tube after treatment by the device in the direction of the arrows E. Suitable supply lines 94 feed the liquid medium into the supply chambers 83 and 85 so that said liquid medium will rotate about the longitudinal axis of the installation. This may be accomplished in any known manner such as by feeding S the liquid medium tangentially into said supply chambers via the supply lines 94 or by means of injection nozzles. The stationary supply chamber 85 is located above the gas intake portion 80. This upper supply chamber 85 is defined by a hollow conical guide member 86 disposed circumjacent the movable nozzle member 84, the lower walls 86a extend downwardly in the direction of the flat surfaces 89 and have the same angle of divergence as the walls of the movable nozzle member 84. Since the liquid medium is also caused to rotate in the upper supply chamber 85, the liquid film will adhere to the walls of the guide tube 86 under the influence of the centrifugal forces. The aforementioned guide tube 86 also serves to protect the liquid medium located in the supply chamber 85 from the gas stream. The liquid medium leaves the supply chamber 85 via the outlet 96 and enters the path of the gas stream in the form of a liquid film adhering to the wall 86a at the lower edge 86b of the guide tube 86. The liquid film from the supply chamber 85 is at least partially atomized in a manner heretofore described together with the liquid medium received from the lower supply chamber 83. In the steadying and separating chamber 87 dis posed below the tubular movable nozzle member 84, the liquid medium now laden with the removed solid particles and the gas are separated. The gas passes upwardly in the direction of the arrows B through the tubular nozzle 84 and, if desired, may be recycled through the system. f course, it is possible to provide a cyclone or labyrinth flow passageway in the separating chamber 87 to aid separation of gas and liquid. The waste water containing the solid particles is gravity fed through the drain pipe 97 and may be recirculated back into the system in a manner as disclosed in FIGURE a.

Due to the provision of an adjustable nozzle unit consisting of the separate relatively movable nozzle members, it is possible to control the nozzle opening in accordance with the volume of incoming gas to thereby ensure that a uniform mixing action is maintained at all times irrespective of any change of the volume of gas fed into the system. Obviously, it is immaterial whether the change of the nozzle opening is achieved by movement of one or both of the nozzle members or whether the nozzle members are moved in a direction parallel with or transverse to the direction of fluid flow. Moreover,

the configuration of the nozzle members may differ, and the cross-sections thereof as well as those of the housing members A shown in FIGURES 1-6 may be replaced by other polygonal or continuously curved members. It is also possible to arrange the surfaces defining a nozzle opening.

in substantially horizontal or obliquely arranged planes with respect to the longitudinal axis of the flow channel. The mixing and purification operation may be enhanced by arranging a plurality of the devices in series which may be of similar or different design and dimension. A proper mixing of the fluid mediums can best be obtained in all cases by adjusting the design of the installation in accordance with the type'of mediums to be handled and the operating conditions thereof.

Surprisingly, it has been found that the removal of dust or other impurities from a gas stream by means of water is particularly effective and economical if the water is recycled and if such water contains solid particles rather than being in a pure state. The difficulty in the performance of a dust removal, or other impurity removal process, by recirculation of the water containing such dust or other solid particles resides in the fact that care must be taken to ensure that such solid particles are not deposited internally of the apparatus. This may be most readily carried out by employing the axially symmetrical arrangements of the mixing and purification devices as depicted in FIGURE .3, 5 and 6.

The teachings of the present invention readily permit construction of a relatively compact dust or impurity removal apparatus. Such is of particular advantage when workingfwith the stack or waste gases of electrical furnaces employing several electrodes, which waste gases are to undergo a cleaning operation. In such an event, it maybe extremely desirable to employ impurity removal devices with each furnace. A further marked advantage of the disclosed device for the removal of dust or other impurities from gases, resides in the fact that a suitable adjustment of the cross-section of the nozzle opening will provide constant velocities of flow even if thesvolume of gas changes, thereby avoiding a change in the efficiency of the system should the latter be operated under varying conditions. It is to be understood that the device is not limited to removal of dust from gases but can be employed to remove any undesirable impurities contained in the gas. Any of the known and conventional conveying devices, such as blowers or pumps, may be employed to transport the gas through the mixing apparatus, which conveying devices may be arranged upstream or downstream of the apparatus in the path of the gas stream.

Having thus described the invention what is desired to be secured by United States Letters Patent is:

1. In a mixing and purification apparatus for fluid mediums, the improvement of; a hollow housing member having a longitudinal axis and internally provided with a flow passageway for fluid mediums, said housing member being provided with an inwardly directed nozzle body member having a flat surface portion and concentrically arranged with respect to said longitudinal axis, a movable nozzle member having a flat surface portion disposed concentric to and in spaced relation with said inwardly directed nozzle body member to define an adjustable nozzle opening, means cooperable with said movable nozzle member to displace the latter to vary the size of said nozzle opening, supply means communicating with said flat surface portions for depositing thereon a liquid medium in film-like manner, said liquid medium cascading and free-falling from said fiat surface portions into said nozzle opening for contact and mixing with a gaseous medium moving in a state of unsteady flow to effectuate atomization of said cascading liquid medium.

2. In a mixing and purification apparatus for fluid mediums, according to claim 1, wherein said supply means include separate supply chambers coaxially arranged in spaced relation from one another.

3. In a mixing and purification apparatus for fluid mediums, the improvement of; a hollow housing member having a longitudinal axis and internally provided with a flow passageway for fluid mediums, said housing member being provided with an inwardly'directed stationary annular nozzle member having a flat surface portion and concentrically arranged with respect to said longtiudinal axis, a movable nozzle member having a flat surface portion disposed concentric to and in spaced relation with said inwardly directed nozzle member to define an adjustable nozzle opening, means cooperable with said movable nozzle member to displace the latter to vary the size of said nozzle opening, supply means including separate coaxially arranged supply charnbers communicating with said fiat surface portions of said movable and stationary nozzle members for depositing thereon a liquid medium in a uniform and continuous film-like manner, at least one of said supply chambers being movable together with said movable nozzle member, said liquid medium cascading and free-falling from said flat surface portions into said nozzle opening for contact and mixing with a gaseous flow passageway for fluid mediums, said housing member being provided with an inwardly directed nozzle member having a fiat surface portion and concentrically arranged with respect to said longitudinal axis, a movable nozzle member having a flat surface portion disposed concentric to and in spaced relation with said inwardly directed nozzle member to define an adjustable nozzle opening, means cooperable with said movable nozzle member to displace the latter to vary the size of said nozzle opening, supply means operatively coupled with said fiat surface portions for depositing thereon a liquid medium in film-like manner, said liquid medium cascading and free-falling from said fiat surface portions into said nozzle opening for con tact and mixing with a gaseous medium moving in a state of unsteady flow to effectuate atomization of said cascading and free-falling liquid medium, said nozzle members being provided with diverging wall portions defining a diffuser member for receiving said atomized liquid medium and said gaseous medium for further intensive mixing thereof.

5. In a mixing and purification apparatus for fiuid mediums, the improvement of; a hollow housing member having a longitudinal axis and internally provided with a flow passageway for fluid mediums, said housing member being provided with an inwardly directed nozzle member having a flat surface portion and concentrically arranged with respect to said longitudinal axis, a movable nozzle member having a flat surface portion disposed concentric to and in spaced relation with said inwardly directed nozzle member to define an adjustable nozzle opening, means cooperable with said movable nozzle member to displace the latter to vary the size of said nozzle opening, supply means including a horizontally extending outlet opening operatively communicating with said fiat surface portions for depositing thereon a liquid medium in film-like manner, said liquid medium cascading and free-falling from said fiat surface portions into said nozzle opening for contact and mixing with a gaseous medium moving in a state of unsteady flow to effectuate atomization of said cascading liquid medium, said nozzle members being provided with diverging wall portions defining a diffuser region for receiving said atomized liquid medium and said gaseous medium for further intensive mixing thereof and removal of impurities from said gaseous medium, said hollow housing member including a separation chamber located downstream of said nozzle members for carrying out separation of said liquid medium and the removed impurities contained therein from said gaseous medium.

References Cited by the Examiner UNITED STATES PATENTS REUBEN FRIEDMAN, Primary Examiner.

HARRY B. THORNTON, WALTER BERLOWITZ,

Examiners. 

1. IN A MIXING AND PURIFICATION APPARATUS FOR FLUID MEDIUMS, THE IMPROVEMENT OF; A HOLLOW HOUSING MEMBER HAVING A LONGITUDINAL AXIS AND INTERNALLY PROVIDED WITH A FLOW PASSAGEWAY FOR FLUID MEDIUMS, SAID HOUSING MEMBER BEING PROVIDED WITH AN INWARDLY DIRECTED NOZZLE BODY MEMBER HAVING A FLAT SURFACE PORTION AND CONCENTRICALLY ARRANGED WITH RESPECT TO SAID LONGITUDINAL AXIS, A MOVABLE NOZZLE MEMBER HAVING A FLAT SURFACE PORTION DISPOSED CONCENTRIC TO AND IN SPACED RELATION WITH SAID INWARDLY DIRECTED NOZZLE BODY MEMBER TO DEFINE AN ADJUSTABLE NOZZLE 